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Graph and Pipeline

Graph and Pipeline is a structural framework for developing q/kdb+ solutions, based on a mathematical directed graph. In mathematics, and more specifically in graph theory, a directed graph is a set of vertices/nodes/points connected by edges, where the edges have an associated direction as shown in the below example:

Directed graph

By defining code using this core idea a user can develop independent sections of code defined by the nodes and connect them together logically to form a full data analysis pipeline.

Writing code this way allows for:

  • Maintenance of a code base is easier due to the individual elements being independent of each other prior to the connection and validation of the graph.
  • Once a ‘wire’ version of the graph has been defined by a team, individual nodes can be developed completely independently. This reduces the chance of parallel lines of development causing issues when merging independent sections of code within a large team.
  • Testing of the code can be structured on a per-node basis or by connecting chains of nodes together. This allows for complex code bases to be tested at a more granular level than may otherwise be feasible.
  • Producing fundamental changes to the code base is less cumbersome than in a less modular framework. Adding a new piece of functionality requires only the addition of a new node, and the removal and reattaching of associated edges.

This extension to the Machine Learning Toolkit consists of:

  • Graphing: Create, modify and remove nodes or edges to a graph
  • Pipelining: Convert a valid graph into an optimized framework, and execute it to evaluate the logic

Find example notebooks at KxSystems/mlnotebooks.

All code relating to the graph and pipeline section of the Machine Learning Toolkit is at


The graph library can be loaded independently of the remaining sections of the ML Toolkit:

q)\l ml/ml.q